We briefly discussed the potential for q-thrusters onboard subs. With that kind of power plant available, if q-thrusters can deliver, that could be huge. That should give the NRL pause. Would give a whole new meaning to silent service. You see I'm trying to whet people's appetites to take a look at q-thrusters.

We've uncovered a plausible theory of operation of these things. Experimental results from multiple teams show performance way in excess of a photon rocket. Every research lab in the country should be taking notice. Never hurts to look.

those mission parameters presupposed electrical power from solar panels? I guess that some good fission or fusion reactors (whenever fusion is available) would allow the addition of even more EM Drives and cut that mission time several times.

Aceshigh:

When it comes to manned solar electric propulsion missions, the largest to date proposed photovoltaic arrays for a human crewed missions are in the 300 kilowatt electric (kW-e) power range. However most of the Q-Thruster solar system based mission analysis we did last year assumed using a U235 fission based reactor with a closed-cycle brayton or rankine thermal to electrical power conversion cycle system in the 1.0-to-2.0 Megawatt electric (MW-e) class output with at least a 10 year lifetime. Now it's true that such a space based nuclear power reactor system has never been fielded, but that was due to a lack of a funded mission for same like sending humans to Mars, but more importantly, the lack of the political will to do so. However building such a space-based closed cycle electrical power reactor is technologically feasible and has been since the 1980s.

Now like all naval propulsion system, once you've established the viability of a propulsion technique like the EM-Drive, and have an urgent need to do so, what comes next is developing the long lead items needed to power it. And all these electric space propulsion concepts for deep-space human missions, be they conventional ion, Hall or VASMIR type plasma rocket thrusters, or Q-thruster like space drives, go begging for an already developed nuclear power plant that is sized from 1.0 MWe up to 100 MWe output dependent on the mission scenario. I know that this sounds like a lot of power to the space community, but when it's compared to what the US Navy already builds for its nuclear submarine fleet like its "Boomer' Ohio class ICBM vehicles, which sport the 220 MW-thermal (MW-t) S8G reactor that fits in a 42 foot diameter by 55 feet long container and lasts for up to 30 years between refueling, its not a lot to ask technically if we just had the real need to do so. And that will always be a political and business decision, not a technical one.

I guess not everyone realizes that a resonant cavity can be represented as an LC circuit. They're all the same thing.

It can be represented by a simple LC circuit only for simple uniform cavities, with uniform cross-sections, as for example the rectangular cross section cavity or the cylindrical cavity.

The truncated cone (frustum) shape used by NASA, Shawyer in the UK and Prof. Juan Yang in China displays degenerate modes that go from resonant to evanescent, and it displays modes that do not conform to the same TEmnp or TMmnp designation as in cylindrical cavities. Actually in reviewing the mode shapes assigned in the COMSOL study for NASA I am now reviewing some interesting cases (the frequencies and images computed by COMSOL are excellent, but the designation of some of the modes is not straightforward, as the NASA engineer realized when designating some of the modes as "X").

There is some flexibility. I remember working on delay lines w/ parameters varying w/ length.

That was odd stuff, I wonder if it can make a resonant circuit that way?

I agree, that's why I wrote "It can be represented by a simple LC circuit only". Yes, with a circuit complicated enough we could probably simulate most electromagnetic wave phenomena, just like the few analog computers that still were being used at MIT Labs in the early 1970's to solve differential equations. I remember those . Reconfiguring the analog computer to solve a different equation required actual handwork unlike just writing software for digital computers :-)

The LC circuit approximation of a resonant cavity is to show the similar underlying mode of operation of all the previous iterations of "q-thrusters." Where Emdrive was more successful than the previous generations is the (unintentional) leveraging of cavity QED. The Emdrive utilizes the principle of confinement to great effect. This isn't to point out any particular failure. These are all valuable lessons learned. Evidence keeps piling up that quantum fluctuations under confinement are amplified if they are resonant or spatially confined. And at the same time the cavity serves to maximize the magnetic field localization and intensity, especially TE012.

those mission parameters presupposed electrical power from solar panels? I guess that some good fission or fusion reactors (whenever fusion is available) would allow the addition of even more EM Drives and cut that mission time several times.

Aceshigh:

When it comes to manned solar electric propulsion missions, the largest to date proposed photovoltaic arrays for a human crewed missions are in the 300 kilowatt electric (kW-e) power range. However most of the Q-Thruster solar system based mission analysis we did last year assumed using a U235 fission based reactor with a closed-cycle brayton or rankine thermal to electrical power conversion cycle system in the 1.0-to-2.0 Megawatt electric (MW-e) class output with at least a 10 year lifetime. Now it's true that such a space based nuclear power reactor system has never been fielded, but that was due to a lack of a funded mission for same like sending humans to Mars, but more importantly, the lack of the political will to do so. However building such a space-based closed cycle electrical power reactor is technologically feasible and has been since the 1980s.

Now like all naval propulsion system, once you've established the viability of a propulsion technique like the EM-Drive, and have an urgent need to do so, what comes next is developing the long lead items needed to power it. And all these electric space propulsion concepts for deep-space human missions, be they conventional ion, Hall or VASMIR type plasma rocket thrusters, or Q-thruster like space drives, go begging for an already developed nuclear power plant that is sized from 1.0 MWe up to 100 MWe output dependent on the mission scenario. I know that this sounds like a lot of power to the space community, but when it's compared to what the US Navy already builds for its nuclear submarine fleet like its "Boomer' Ohio class ICBM vehicles, which sport the 220 MW-thermal (MW-t) S8G reactor that fits in a 42 foot diameter by 55 feet long container and lasts for up to 30 years between refueling, its not a lot to ask technically if we just had the real need to do so. And that will always be a political and business decision, not a technical one.

Best, Paul M.

But unlike all the conventional electric space propulsion concepts(1) propellantless schemes have a potential for practical unlimited power generation as soon as around tpr = 1N/kWe is proven, by mounting driver(s) on a rotor linked to a generator of efficiency n and having a tangential speed above 1/(n * tpr). See attached picture.

The only caveat I see would be if wakes of successive passages at same place would interfere and lower the effective thrust power ratio below over-unit cycle. Even in this case I don't see how an over-unit power generating system would still be impossible : use a larger rotor (tethered... many km apart if needed) to give more time for hypothetical wakes to dissipate, use a linear scheme...

So, assuming better than 1N/kW can be reached, why bother with conventional energy generators ? Because we would want to convince ourselves that this is not breaking energy conservation and avoid the "free energy" tag ? But it is not "worse" to posit apparent cheap energy than to posit apparent cheap momentum, and from an engineering point of view it makes no sense to use the later and refusing to see the possibility to use the former.

First of all. I am just one of many enthusiasts of EmDrive (from central Europe). I think I read all I can about it and follow it for quite a while.

I am wondering about few things. Mr. Paul March, if you can answer, that would be great as well. I see that you said you lack the funds (resources) to continue important tests on the EmDrive. This is definitely a project that cought attention of many in the world (and deserves much more media attention as it can be really revolutionary). Many projects that need to be financed heavily go for support at Kickstarter and many other similar websites. Perhaps it can help you? Also it can bring more media attention. I know that in the past NASA did few of those steps that help them to bring attention to them one way or the other to succeed.

There is also another thing I am wondering about and I would be glad if you guys can help me answer it.NASA do not mention too much Mr. Roger Shawyer. Is it perhaps to try to stay as much independent as possible in their research? I hope that some time in the future all the scientits and engineers that work on this kind of technology (from Mr. Shawyer, Mr. Fetta, NASA team and chinese team as well) will make some nice conference on this. It can bring you a lot of public attention (and not enough space for proper reasearch I guess ).

But unlike all the conventional electric space propulsion concepts(1) propellantless schemes have a potential for practical unlimited power generation as soon as around tpr = 1N/kWe is proven, by mounting driver(s) on a rotor linked to a generator of efficiency n and having a tangential speed above 1/(n * tpr). See attached picture.

The only caveat I see would be if wakes of successive passages at same place would interfere and lower the effective thrust power ratio below over-unit cycle. Even in this case I don't see how an over-unit power generating system would still be impossible : use a larger rotor (tethered... many km apart if needed) to give more time for hypothetical wakes to dissipate, use a linear scheme...

So, assuming better than 1N/kW can be reached, why bother with conventional energy generators ? Because we would want to convince ourselves that this is not breaking energy conservation and avoid the "free energy" tag ? But it is not "worse" to posit apparent cheap energy than to posit apparent cheap momentum, and from an engineering point of view it makes no sense to use the later and refusing to see the possibility to use the former.

(1) except electrodynamic tether used as generator, but at the cost of absorbed deltaV : that is a 0 sum game...

Similarly, Maxwell himself conceived a demon (as a thought experiment) to demonstrate how to violate the Second Law of Thermodynamics: a container of gas molecules at equilibrium is divided into two parts by an insulated wall, with a door that can be opened and closed by what came to be known as "Maxwell's demon". The demon opens the door to allow only the faster than average molecules to flow through to a favored side of the chamber, and only the slower than average molecules to the other side, causing the favored side to gradually heat up while the other side cools down, thus decreasing entropy.

One of the famous responses was by Leon Brillouin that shows that the second law of thermodynamics will not actually be violated, if a more complete analysis is made of the whole system including the demon. Any demon must "generate" more entropy segregating the molecules than it could ever eliminate by the method described by Maxwell.

In the case of the EM Drive, to answer the "overunity" question one has to perform a complete analysis of the whole system. This cannot be done in isolation, without a theory of operation for the EM Drive. It would be like arguing that a windmill or a sailing boat cannot move (in an analysis ignoring the wind) because it would be a source of practical unlimited power. Same thing with extracting energy from the ocean. In the case of the EM Drive, due consideration of the total system is required: whether coupling with the Quantum Vacuum, or coupling with any other external field.

At this early stage, no theory proposed has quantitatively and scientifically answered how momentum is conserved, or has properly addressed the entire system to answer whether the 2nd law of thermodynamics is respected.

So energy in a box (whatever forms) has inertial and gravitational mass, all right. But I fail to see how it explains how em drive cant go over unity. I don't see why it shouldn't go apparently energy over unity in the first place, it is not a more inconvenient problem than it goes apparently non 0 net momentum.

If you insist on this apparent net energy generation being impossible, then please explain how a emdrive used as a linear thruster fed by conventional energy source can impart a (hypothetically) velocity invariant fixed thrust/power ratio to a spaceship, and the same thruster mounted tangentially on a flywheel wouldn't show the same thrust/power ratio ? Where and why exactly the depicted "unlimited energy generator" would fail ?

If the energy generation scheme don't work then reciprocally it would imply that there is some dependence of the thrust/power ratio on some preferred rest frame and/or total integrated "use" of the effect, and that would seriously impede mission profiles (of emdrive fed by conventional mean) : all published mission profiles so far have worked under the assumption of constant thrust/power ratio even beyond the point of acquiring more kinetic energy than spent electric power. And that is precisely what makes them much better than conventional high Isp action/reaction, like Vasimr, most on overunity energy gain, not a lot on saving propellant mass. In the very same papers, the attempts at considering limitations to prevent such apparent over-unity were not applied in the mission profiles chapters.

So my point is, this should be consistent :- Either thrust/power is invariant, the mission profiles are OK and apparent overunity generator is also possible to power them up.- Thrust/power is not invariant, apparent overunityimpossibility of energy generation might be enforced, but the mission profiles are to be seriously shaved down.

In any case, a system wide analysis would show both momentum and energy conservation (taking into account QV state before and after operation, for instance), the net momentum and energy gain being only apparent. We shouldn't shy away from apparent energy overunity gain, this is not more "free energy" than it is "free momentum".

In the case of the EM Drive, to answer the "overunity" question one has to perform a complete analysis of the whole system. This cannot be done in isolation, without a theory of operation for the EM Drive. It would be like arguing that a windmill or a sailing boat cannot move (in an analysis ignoring the wind) because it would be a source of practical unlimited power. Same thing with extracting energy from the ocean. In the case of the EM Drive, due consideration of the total system is required: whether coupling with the Quantum Vacuum, or coupling with any other external field.

Exactly, so we can't rule out the possibility of apparent energy overunity before (the reality of the effect is proven beyond any doubt and) there is a working theory than can encompass the "total system". But the point is, even before we have such working theory that would show how both energy and momentum conservation are guaranteed, we have an experimental/phenomenological prediction of a given thrust/power in a (Lorentz invariant) vacuum, if this is to hold for propulsion (and giving a ship more kinetic energy than spent electric power) then this is to hold for energy generation, regardless of the deeper theories.

I don't mean to sound insistent, but I feel a lot of resistance about that important empirical fact, more for sociological reasons than real scientific logic.

In the case of the EM Drive, to answer the "overunity" question one has to perform a complete analysis of the whole system. This cannot be done in isolation, without a theory of operation for the EM Drive. It would be like arguing that a windmill or a sailing boat cannot move (in an analysis ignoring the wind) because it would be a source of practical unlimited power. Same thing with extracting energy from the ocean. In the case of the EM Drive, due consideration of the total system is required: whether coupling with the Quantum Vacuum, or coupling with any other external field.

Exactly, so we can't rule out the possibility of apparent energy overunity before (the reality of the effect is proven beyond any doubt and) there is a working theory than can encompass the "total system". But the point is, even before we have such working theory that would show how both energy and momentum conservation are guaranteed, we have an experimental/phenomenological prediction of a given thrust/power in a (Lorentz invariant) vacuum, if this is to hold for propulsion (and giving a ship more kinetic energy than spent electric power) then this is to hold for energy generation, regardless of the deeper theories.

I don't mean to sound insistent, but I feel a lot of resistance about that important empirical fact, more for psychological reasons than real scientific logic.

At this early stage, no published theory has precisely, mathematically modeled how momentum is conserved, or has mathematically modeled the entire system to answer how the 2nd law of thermodynamics is respected in the EM Drive.

Physics (since Newton) is an applied mathematical as well as an experimental science. Until these questions have been answered mathematically, solely and precisely , they are still a subject of conjecture and hypothesis.

Quote from: Von Neumann

The sciences do not try to explain, they hardly even try to interpret, they mainly make models. By a model is meant a mathematical construct which, with the addition of certain verbal interpretations, describes observed phenomena. The justification of such a mathematical construct is solely and precisely that it is expected to work.

No mathematical model has been published yet that "solely and precisely" mathematically models the observed phenomena of the EM Drive. To make an imprecise analogy, before Heissenberg, Schrodinger and Von Neumann published mathematical solutions, and the theoretical framework of Quantum Mechanics, big questions about the then mysterious Quantum Mechanics could not be answered cathegorically either.

those mission parameters presupposed electrical power from solar panels? I guess that some good fission or fusion reactors (whenever fusion is available) would allow the addition of even more EM Drives and cut that mission time several times.

Aceshigh:

When it comes to manned solar electric propulsion missions, the largest to date proposed photovoltaic arrays for a human crewed missions are in the 300 kilowatt electric (kW-e) power range. However most of the Q-Thruster solar system based mission analysis we did last year assumed using a U235 fission based reactor with a closed-cycle brayton or rankine thermal to electrical power conversion cycle system in the 1.0-to-2.0 Megawatt electric (MW-e) class output with at least a 10 year lifetime. Now it's true that such a space based nuclear power reactor system has never been fielded, but that was due to a lack of a funded mission for same like sending humans to Mars, but more importantly, the lack of the political will to do so. However building such a space-based closed cycle electrical power reactor is technologically feasible and has been since the 1980s.

Now like all naval propulsion system, once you've established the viability of a propulsion technique like the EM-Drive, and have an urgent need to do so, what comes next is developing the long lead items needed to power it. And all these electric space propulsion concepts for deep-space human missions, be they conventional ion, Hall or VASMIR type plasma rocket thrusters, or Q-thruster like space drives, go begging for an already developed nuclear power plant that is sized from 1.0 MWe up to 100 MWe output dependent on the mission scenario. I know that this sounds like a lot of power to the space community, but when it's compared to what the US Navy already builds for its nuclear submarine fleet like its "Boomer' Ohio class ICBM vehicles, which sport the 220 MW-thermal (MW-t) S8G reactor that fits in a 42 foot diameter by 55 feet long container and lasts for up to 30 years between refueling, its not a lot to ask technically if we just had the real need to do so. And that will always be a political and business decision, not a technical one.

Best, Paul M.

S8G weight 2750 tons?BiiiiiiiiiiiigFR needed.

We used 10.0 kg/kW-e in our Q-Thruster mission analysis for our nuclear power plant specific mass, see chart. This figure could be reduced further to around 5.0 kg/kW-e or even lower with sufficient R&D funding, but still based on a fission based uranium/nitride (UN) fuel and a CO2 supercritical power conversion cycle.

For those of us who have become completely lost in the math, can you, in layman's terms, explain what everyone seems to SUSPECT is going on when it comes to converting electrical current into motive force?

I've tried to follow the math, but was lost a while back, and the best I can understand is that somehow it involves Vaccume Energy and possibley Dark Matter

Assuming that the EM Drive effectively work*, it means you are somehow "stealing" energy from somewhere, and that you can create something which looks like perpetual motion. Let's say that the "somewhere" is the quantum void (QV). Since it can't have an infinite energy, it must mean that you can somehow deplete QV energy.

I'm not a specialist, but I think the question "What is the value of the vacuum energy of free space?" becomes relevant here. Additionally it raises disturbing (for me at least) questions, like "What happens when QV energy is depleted?".

Edit: *what I mean here by "work" is "is a system which, given electrical power, produce a force, regardless of its medium, non-relativistic speed, orientation etc..."

For those of us who have become completely lost in the math, can you, in layman's terms, explain what everyone seems to SUSPECT is going on when it comes to converting electrical current into motive force?

I've tried to follow the math, but was lost a while back, and the best I can understand is that somehow it involves Vaccume Energy and possibley Dark Matter

Much of the work in this thread has not been focused on theories of operation. Most of the recent math has been focused on attempts to amplify the observed effect, for the sake of demonstrating that it is a real effect, rather than experimental artifact.

There is not a consensus on the cause of the apparent thrust, be it real or imaginary. Suggested causes of real thrust include interactions with dark matter, harnessing linear momentum from the quantum vacuum, evanescent waves creating inertial moments, tapping into photons being the source of momentum in the universe in general... there's a lot of ideas out there. What all of these theories are short on is experimental data. Because there is no money (Eagleworks is not allowed to accept crowd funding), right now is the time to think.

For those of us who have become completely lost in the math, can you, in layman's terms, explain what everyone seems to SUSPECT is going on when it comes to converting electrical current into motive force?

I've tried to follow the math, but was lost a while back, and the best I can understand is that somehow it involves Vaccume Energy and possibley Dark Matter

Much of the work in this thread has not been focused on theories of operation. Most of the recent math has been focused on attempts to amplify the observed effect, for the sake of demonstrating that it is a real effect, rather than experimental artifact.

There is not a consensus on the cause of the apparent thrust, be it real or imaginary. Suggestions for causes of real thrust include interactions with dark matter, harnessing linear momentum from the quantum vacuum, evanescent waves creating inertial moments, tapping into photons being the source of momentum in the universe in general... there's a lot of ideas out there. What all of these theories are short on is experimental data. Because there is no money (Eagleworks is not allowed to accept crowd funding), right now is the time to think.

As an analogy, what does "everyone seems to suspect" is Dark Matter? what does "everyone seems to suspect" is Dark Energy? what does "everyone seems to suspect" is the Unified Theory that could unify Quantum Mechanics and Relativity? what does everyone think is Time? what does everyone think is the ultimate nature of the Universe: continuous or discrete ? and so on...

There is no consensus in the scientific community at large either on these questions, and many more, to which much, much more money and brains have been dedicated to. The answers to the above questions, from respected scientists, cover a large number of hypotheses (some of the theories on "Dark Matter" are that it is not really matter, in our spatial universe). Similarly here in this thread no consensus can be expected. What can be expected is to eliminate theoretical explanations, and to examine theory, numerical models and experiments in detail, with scientific thoroughness. Some possibilities for how an EM Drive could work for space propulsion have been strongly shot down in this thread. One of the possibilities that has been studied in some detail, mostly in Thread 1 and some in thread 2 is that the possibility that Dark Matter is responsible for EM Drive thrust measurements is very, very remote, see for example the posts by Astrophysicist Marshall Eubanks:

The key take away from the light in a box page was the red shift/blue shift. The same thing is presented by Shawyer. Also the theory paper presented (see Colbert) explains precisely how momentum is conserved. There is no free/cheap momentum.

Asserting there are conservation issues /while at the same time not understanding the interaction doesn't make sense. That's like passing legislation governing the use of time travel and warp drive before they become real. Just speculation.

Assuming that the EM Drive effectively work, it means you are somehow "stealing" energy from somewhere, and that you can create something which looks like perpetual motion. Let's say that the "somewhere" is the quantum void (QV). Since it can't have an infinite energy, it must mean that you can somehow deplete QV energy.

I'm not a specialist, but I think the question "What is the value of the vacuum energy of free space?" becomes relevant here. Additionally it raises disturbing (for me at least) questions, like "What happens when QV energy is depleted?".

I don't think you are looking at it correctly. Are you stealing from the earth's gravity when you do a push-up? Of course not.

Gaining potential energy by acting against gravity is well known to respect conservation of energy.

The Emdrive, if it works as a legit interaction with the QV as H. White and some posters here believe, would act more like a windmill or a sail ship. You could potentially be taking energy from the quantum vacuum, but for you it would indeed be "free energy". In the same sense as a windmill provides you with "free energy" from an external source (the wind).

With the difference the external source for the Emdrive would be the QV, which is everywhere.

I have to note that besides the actual existence of this phenomenon, it is not clear either if the momentum gain is limited or not or if it is restricted with respect some background field/reference frame. I'm assuming it's not, that is, the amount of acceleration is the same regardless of the inertial frame of reference.